


Self-Sworn

by NinjaDragonWhat



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alternate Universe - Fantasy, Caspar is a sort of wandering mercenary, Flayne aka Cethleann is Lin's familiar, High Fantasy, Linhardt is Very Lost, M/M, Slow Burn
Language: English
Status: In-Progress
Published: 2020-08-19
Updated: 2020-08-25
Packaged: 2021-03-06 02:06:48
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,236
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25985605
Author URL: https://archiveofourown.org/users/NinjaDragonWhat/pseuds/NinjaDragonWhat
Summary: When Caspar stumbles upon a mysterious mage in the middle of a forest, he assumes the man is either lost or careless. But there's more to Linhardt's story then that, and as the pair begins a strange partnership on their journeys, they realize that the story of two  adventurer's is often far more interesting then quests done solo.
Relationships: Caspar von Bergliez/Linhardt von Hevring
Comments: 3
Kudos: 14





	1. Chapter One

**Summary for the Chapter:**

> Caspar meets a traveling companion

**Notes for the Chapter:**

> Howdy! This is my first fanfic for this fandom, which I of course decided to start a week before college starts. Woohoo!
> 
> Think of this as a sort of prologue, of sorts. I'm hoping to make the chapters after this a bit longer.
> 
> This work is heavily inspired by my recent reading of the Oathbound series by Mercedes Lackey. If you're into classic high fantasy with female protags, give her a read!

Being a second son had only bothered Caspar when it was most superficial, often when he was running low on gold. But after that- he couldn’t care less. Second sons had more freedom. Second sons weren’t expected to do much besides stay out of their older brother’s way.

And stay out of the way Caspar had. He’d spent his childhood in guard’s barracks and under tavern tables, soaking in adventure stories and fighting techniques and the unique code of honor one can only get from a lifetime of mercenary work. The only books he ever read were grand tales of heroic knights, and the only persuasion he had to learn was wheedling a training session or two out of seasoned veterans passing through town.

And then he’d turned 18, packed up his meager belongings, and told his brother to not worry about him ruining any potential weddings with his too-boisterous laughter. He’d set off, then, to fight for a living, to right wrongs, and to prove himself a warrior without compare.

Now, two years later, he was out camping in the infamous Sealed Forest. Right now, his biggest goal was to sleep in a bed soon.

Nights in the southern forest were dark and full of monsters, so traveling anywhere alone was risky enough as it were. Caspar was even worse off, without even a candle to light his path, let alone the mage-lights recommended by anyone who’d been through the pass before. It had gotten too dark to see far too quickly, and he’d been forced to make camp, right there in the middle of the road.

He’d almost gotten to sleep in his bedroll when the wind picked up. It was a soft, unnatural-feeling breeze that brought with it the scent of angelica, and Caspar stirred, sitting up and blinking blindly around at the dense trees surrounding him. They offered no advice or answer, only swaying along with the sweet-smelling air. Caspar grumbled something to himself, pulling his axe closer to him on the ground, and made to sit back down.

_My master requests aid,_ a silvery voice breathed in his mind. Caspar jerked wide awake.

“Who’s there?” He brandished his axe wildly around him, seeking an invisible foe. The silvery voice laughed in his head, a tinkling noise that reminded him of his mother’s evening jewelry.

_I am Cethleann, humble servant of the good mage Linhardt. He is in dire need, and I am here to request it of you._

Caspar didn’t know anything about mages, or magic, or who Cethleann was, but he knew that he’d promised himself to always strive to help others. “Lead me,” he called into the floral-scented wind, rolling his bedroll with practiced efficiency. “I’ll run.”

And lead the voice did, spinning its wind to push in the direction he ran. Caspar, despite the fact that someone might be in grave danger, found himself growing excited. He had never rescued someone in the two years he’d been traveling, and as of recent his most exciting fights were with bandits who’d grown too confident. He relished the chance to play the chivalrous knight.

He’d forgotten to put on his armor, but oh well. Maybe that would make it look so much cooler when he swept in to save the day.

He knew immediately what was up when he saw it: a ring of bright lights surrounding a clearing, bobbing in the night air, characteristic of mage-work. Caspar gave himself a final push of speed and burst into the circle, axe at the ready and pointed at-

A tall, slender creature with white hair and hollow eyes. Caspar grit his teeth, grinning. Fey, as tricky as they wanted to be, were no match for him and his iron-forged axe.

The fey, which had been hovering over a far more humanoid figure huddled on the ground, turned and hissed at Caspar, long fingers reaching out to claw him. He was too quick for the sapling, though; he spun easily out of its reach and cut it with one decisive swing. It gave a screech reminiscent of a felled dead tree, then toppled, turning to leaves and mushrooms where it lay.

A young one, then. Caspar felt mildly disappointed. He’d been hoping for something a bit more exciting.

His proverbial damsel in distress cleared his throat, and Caspar turned to get a good look at him. He had long, elegantly tied back hair the color of emeralds, his eyes a stormy blue. He wore the unmistakable robes of a mage, though Caspar saw no crest identifying a school, which was odd. The man yawned. “I suppose you were the help I sent Cethleann after?”

Caspar grinned down, offering a hand to help the man up. His hands were small and delicate, uncalloused, a contrast to the scarred and work-worn skin of Caspar’s own. “What was that, anyway? I’m not used to voices in my head.”

“She’s my familiar,” the mage said, his voice dismissive, as if it were of no concern to him. “I suppose I thank you now, then? You did save me an awful lot of trouble.”

It was an odd way of saying thanks, but Caspar hardly minded. He grinned wide and stuck out his hand, the lightning-excitement stirring back up in him. “I’m Caspar. You know, it’s actually fortunate I met a mage here. Roads are terrible without one.”

They met hands again, and this time Caspar noted how soft the other man’s hands were. They were like that of a noblewoman’s, of someone never required to do anything with them. “Linhardt. You’re quite overzealous with your swings.”

“What does- never mind.” Caspar tilted his head, trying again to find a school crest. Usually they were out in the open, proudly displayed, for bragging rights and prestige. “Uh. What school are you? Your, ah, familiar only called you a good mage.”

“That’s just her way of talking,” Linhardt said breezily, also taking stock of the man in front of him with a lazy gaze. “I’m self-taught, if you must know, though I don’t find how that’s relevant.”

The discussion was interrupted by the unmistakable howling of a red wolf, and Caspar took a defensive stance out of habit. Linhardt sighed, sitting back down and brushing off the front of his robes like the whole situation had been frazzling. “There’s a protective ward. Mundane creatures can’t get through.”

“Oh,” Caspar said, relaxing his pose, because he didn’t know what else to say. “Um. That sounds really helpful.”

Linhardt hummed an agreement, curling up on the bare ground. Caspar watched in something that was almost fascination. “Aren’t you… cold, down there?” His excitement was growing, despite the fact that this mage was not the legendary spellcaster of tales of old. Knights always had mages as companions, right? “I know for a fact it can’t be comfortable. The ground here is hard as rock.”

“Do you have a better idea?” Linhardt yawned again, stretching out like a cat. “It’s not like I have a bedroll.”

“Don’t have a- what are you doing out in the middle of the forest without any provisions?” Caspar, without thinking, pulled out his own, launching into a vibrant lecture on the importance of preparedness and how easy it was to get sick if one slept straight on the ground. He realized halfway through a speech about campsite etiquette that he was rambling, and tapered to a stop. “Oh. Sorry about that. Uh, you can use mine for tonight.”

Linhardt, who had been watching him the whole time he was talking with something like amusement in his eyes, cocked his head to the side, causing his long hair to cascade over one shoulder. Caspar found himself watching it flow, the green locks somehow fascinating. “I thought you said it’s important not to sleep on the bare ground. You would offer a stranger your bed?”

“I’m not a monster!” Caspar said, offended the mage would even imply he’d leave him to fend for himself. “And besides. I just had to save you from a sapling. You’re obviously not prepared to be out in these woods all alone.”

A comfortable silence settled between them, as Caspar used the light of Linhardt’s magelights to set up a proper camp. Once he had a fire going, he was about to ask if the other man was hungry when he realized how late it was. Or rather, early. He could see the warm light of sunrise starting to creep across the sky. His new companion didn’t seem to notice; Linhardt was already curled up in Caspar’s bedroll, his breath even and slow.

“I’ll let him rest,” Caspar said quietly to himself. “Who knows what he’s been through on his travels, if he’s this unprepared.”


	2. Chapter 2

**Summary for the Chapter:**

> Names are given, and received

Linhardt looked a lot less elegant after sleeping for 6 hours, though Caspar found that endearing, in a way. His green hair had gotten tangled in his sleep, bits and pieces fluffing out in ways that made Caspar snort. The man himself was no better; he’d crawled out of the bedroll, his yawns obvious and frequent, asking about breakfast.

“Since when am I in charge of keeping you comfortable?” Caspar complained, without heat. He’d been planning on feeding the both of them anyway, but he couldn’t help but tease. Linhardt made a face, and blinked blearily at Caspar. He was- pouting. It was adorable. Caspar quickly turned back to stoking the fire.

“Well, I certainly don’t know how to. And you seem the more prepared of us two.” Linhardt shuffled over to sit next to Caspar. “Besides, it’s a terrible effort. It would probably just make me tired again. And as much as I enjoy napping, I’d rather be in this forest as little as possible.” He leaned casually into Caspar’s side, as if it were the most natural thing to do. “Where are we, anyway?”

“The Sealed Forest?” Caspar said, trying to ignore the way his ears got hot as Linhardt rested against him. “You know, the forest that’s so dangerous merchants spend hundreds of gold going around it rather than through? Did you seriously walk in here without knowing where you were going?”

“I didn’t walk.” Linhardt yawned again. “Cethleann teleported me here.”

Caspar blinked down at him. “You just… teleported here? Without preparing?”

“I didn’t know I was going anywhere,” Linhardt defended, sounding bored. “I got into an argument with my father, and she feared for my life, so she moved me. Had I known what was going to happen, I would’ve at least brought a pillow.” He shifted, resting his head on Caspar’s shoulder. “Hmm. Maybe a blanket, too.”

Caspar now had several things to process, least of all the warm weight of a very pretty man against his arm. “So you don’t have any supplies at all?” His concern was growing, for many reasons. The Sealed Forest was known for having dangers at every turn, but more than that, someone unprepared could hardly survive in a regular forest, let alone one that was notorious for its hives of Fey and tricky paths.

“Nope.” Linhardt yawned yet again.

  
“Are you always this tired?” Caspar asked, shrugging Linhardt off to get food from his pack, earning a huff of indignation in the process.

“I simply find great joy in the comfort of unconsciousness.”

“Huh.” Caspar couldn’t imagine feeling like that at all. In fact, he often wished the opposite- that he didn’t need sleep, so he could cover more ground and get more done. Sleep was an inconvenience more often than not, though he’d be lying if he said he didn’t enjoy a good nap in the comfort of a warm bed now and again. “Well, you won’t be able to nap much while traveling, so I guess you’ll have to take it where you can.”   
  


“Am I coming with you, now?” Linhardt was feigning disinterest, but Caspar would’ve sworn he heard something like hope in his voice.

“Of course you are! If I left you on your own you’d definitely die. Knights don’t just let people die.” Caspar did not mention that he was not an actual knight; it just sounded cooler than ‘Mercenary’.

He wasn’t lying, either, at least not fully; he would never leave someone to fend for themselves, as unprepared as Linhardt was. But it was more than that. Caspar had found that one of the biggest problems he faced on his chosen path was loneliness. He had always been a social man, and in town that wasn’t an issue, but you were out in the middle of a forest at night all alone, the reality of a lot of things tended to settle on you like a rock. Caspar never slept well while camping, and not just because he was sleeping on the ground.

“I appreciate it greatly,” Linhardt said, leaning over to pluck a roasted piece of meat out of the campfire. “I’d have surely died without you.” There was an edge of sarcasm to his voice, but Caspar puffed up in pride nonetheless.

They talked more over breakfast and as Caspar packed up camp, though most of it was Caspar; Linhardt seemed content to listen, and Caspar relished the chance to finally regale someone with his adventures. It was unusual for someone to let him talk so much. Often had he been told he was “too much”, a sentiment Linhardt did not, at least openly, share.

“...And then I was going to take a boat, but it’s so expensive, and a little camping never hurt anyone, so here I am!” Caspar threw the last of his belongings in his pack and stretched. Are you ready? If we make good time, I think we can make it out of this forest by nightfall!”

“You think?” Linhardt’s voice held no heat, and his lips curved up slightly.

“Yeah, if you don’t nap every five minutes!”

Despite Linhardt’s earlier threats of drowsiness the pair made quick time, and Caspar’s estimate turned out to be correct. The forest soon began thinning, so that the branches weren’t nearly so suffocating, and sunshine now peeked easily through the leaves to dapple the ground in soft yellows.

  
Caspar found himself glancing at Linhardt often, mulling over what he’d told him about his arrival to the forest. What could his father have done that had been so life-threatening? Caspar’s dad had a temper, sure, and there were times in his childhood where he’d been reduced to a quivering mess by his wrath. But even then- Caspar didn’t think he’d ever been in danger of death. Injury, yes, but never anything worse than bruises and the occasional sprain.

He looked over at Linhardt again. He looked sleepy, as Caspar had come to realize he always did, but his eyes still held a sort of spark to them. In the gold light of late afternoon they sparkled, reminding Caspar of the way the ocean looked on sunny, cloudless days. His hair could’ve blended in with the surrounding trees, deep green and shiny, and Caspar briefly considered how it would feel to run his fingers through it.

With a shake of his head, Caspar turned his gaze back towards the path. It wouldn’t do him any good to ponder the looks of his new companion, especially when a misstep might mean a twisted ankle.

“What’s your last name?”

Linhardt’s voice started Caspar, as he’d been near silent since they’d left camp. He was gazing at Caspar with genuine curiosity now. “You hold yourself like a fighter, but there’s something different about you. Were you raised as a mercenary?”

“Ehm. No,” Caspar muttered, nervously. “Uh, where are you from, again?”

“Answer my question first.”

Fair. “Von Bergliez.” He glanced over to gauge Linhardt’s reaction, but the man’s expression remained the same. “Do you uh. Know them?”

“Distantly,” Linhardt replied, twirling a strand of his emerald hair around his finger. “Was it your father, then, that caused the Burning Flood?”

Caspar winced, tightening his hands into fists as he stared straight ahead. “Yeah. That was him.”   
  


The Burning Flood had happened when Caspar was only a baby, so he couldn’t recall anything about it from memory. But he’d figured out what it was pretty quickly, from tavern gossip and whispering servants, and it had always been something he hated about his name.

His father, being a noble, had decided he wanted a hunting cabin. There was a corner of his estate that would’ve been perfect- except that it was infested with elementals, fey, and spirits of all kinds. Generally, one left these creatures alone; they were a pain to fight and the effort often wasn’t worth it.

Caspar’s father, however, had always been a stubborn, bull-headed man. He’d ordered his troops to be decked and armed with iron, and marched them into the thick of the wild corner.

Nobody knows exactly what happened after that, as not a single soldier returned from the crusade. But exactly three days later, a river of flame had burst out of the earth, destroying acres and acres of farmland and devouring whole villages. The whole incident was responsible for the famine that gripped the area for years after, and House Bergliez would’ve lost their noble title because of it if Caspar’s father hadn’t pulled a fair amount of strings and cashed in a favor or two.

Linhardt must have noticed the way Caspar’s shoulders stiffened, as he said, “Well, it wasn’t you, was it? You’re out here adventuring, so you must be nothing like your father.”

It was such a surprisingly sweet thing for Linhardt to say that Caspar nearly laughed. “Thanks, but that doesn’t change the fact that I still carry his name.”

An awkward silence hung between them for a while, the only sound Caspar’s muffled footsteps. Linhardt, interestingly, made almost no sound as he moved. Caspar was about to apologize for being curt, but Linhardt spoke first.

“I’m from a village near the Ruby Lights Forest.” Linhardt was cupping his hands together, as if in deep thought. “My last name is… Von Hevring.”

“Oh.” Caspar had never heard the name before, but he had heard of the Ruby Lights Forest. “Isn’t that place infested with fey?”

“One could say that, yes.” Linhardt was still staring at his hands.

“How could you not fight off that sapling, then? I’d expect you’d be used to dealing with them, being so close to so many.”

“I was… a very sheltered child.” Caspar suddenly recognized with great clarity the tone Linhardt had taken.

“ _ Aaahhh. _ An only child?”

Linhardt looked up at him then, grinning. It was the first genuine smile Caspar had seen from him, and he decided immediately that it was a good look for him. “Yes. So as you can imagine, I never had to fight fey myself.”

Caspar grinned back. “Well, that’s okay, because I can take on anybody who challenges us!” To emphasize his point, he swung his axe triumphantly into the air. Linhardt ducked, alarmed.

“Please watch where you swing that!” But Caspar was not to be deterred. He roared with laughter, holding his weapon up high above his head, as if declaring some oath to the heavens.

“My name is Caspar, and I will defend you with my life!” He yelled, his voice echoing upwards into the sky. Linhardt sighed, but the quirk of his lips betrayed his amusement.

“Well, then. My name is Linhardt, and I’ll patch you up.”

**Notes for the Chapter:**

> I'm 90% certain the only reason I've manage to kick out another chapter is because I've read through the entire casphardt tag on Ao3 now. Twice.
> 
> College starts tomorrow for me, but I'll try my best to keep updating in a somewhat timely fashion!
> 
> Love you guys!

**Author's Note:**

> Shoutout to my loving friends, who indulged me and read this over to give their feedback. I cherish ever single one of you.
> 
> I'm planning to continue this, I'm not sure how long it'll be yet but I'm shooting for something like 6 chapters
> 
> Constructive criticism is always welcome! I eat up critiques like candy. You can find me @ninjadragonwhat on tumblr, twitter, and instagram, though I'm most active on the latter.


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